1. Field of the Invention
The present invention relates to a method of regenerating a vacuum pumping device.
2. Description of the Related Art
Conventionally, molecules trapped in a vacuum pumping device are degassed by a process called regeneration. This process includes raising the temperature of a molecule trapping chamber such as a cold trap to room temperature, discharging the gas in which the trapped molecules are present, evacuating the trap, and lowering the temperature of the trap.
The trapped molecules must be discharged periodically while the temperature of the trap is returned to that of the atmosphere. In order to achieve this, the operation of the devices for lowering the temperature of the trap is temporarily stopped to raise the temperature of the gas in which the trapped molecules are present to room temperature and thereby transform the trapped molecules into a vapor state. Thereafter, the gas in which the trapped molecules are present is discharged into the atmosphere.
As stated above, in the conventional regeneration of a vacuum pumping device, the temperature must be raised to room temperature and then lowered to a low value again. Furthermore, the interior of the device is exposed to the atmosphere and the device is evacuated. Thus, a long regeneration time is required, and contamination of the device may occur due to exposure of the interior thereof to the atmosphere.